Types and Selection Guide for Pneumatic Valve Accessories

Pneumatic valves are widely used in automated control systems for various industrial applications. To enhance their performance, reliability, and efficiency, pneumatic valve accessories play a critical role. These accessories support the core functions of the valve and optimize its responsiveness and adaptability to different control environments.

In this article, we will introduce the main types of pneumatic valve accessories, their functions, and provide a selection guide to help users choose the right components based on system requirements.

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Common Pneumatic Valve Accessories

Air Preparation Units (FRL units)

Comprising an air filter, pressure regulator, and lubricator, these units are essential for purifying and stabilizing the air source. Known as “pneumatic air treatment triplets,” they serve a role similar to a transformer in electrical systems — ensuring clean, dry, and properly pressurized air reaches the pneumatic instruments.

Pneumatic Actuators

Double-acting actuators: Used for two-position control (open/close) by supplying compressed air to both sides.

Spring-return actuators: Automatically open or close the valve upon air or power failure (fail-safe design).

Solenoid Valves

Single solenoid valve: Operates the actuator when powered and returns to the default position when power is off. Explosion-proof versions are available.

Double solenoid valve: One coil opens the valve, the other closes it, providing memory functionality.

Limit Switches (Valve Position Monitors)

These devices transmit remote feedback signals indicating the open or closed position of the valve. Explosion-proof types are also available.

Positioners

Electro-pneumatic positioner: Adjusts valve opening based on a standard 4–20 mA current signal.

Pneumatic positioner: Adjusts valve opening based on an air pressure signal (0.02–0.1 MPa).

I/P converter: Converts an electric current signal to a pneumatic pressure signal, often used in combination with pneumatic positioners.

Pneumatic Valve

Manual Override Mechanism

Ensures manual operation of the valve during emergencies or control system failures.

How to Select Pneumatic Valve Accessories

Selecting the right accessories is crucial for achieving desired control performance in a pneumatic system. Below is a guide to key selection considerations:

1.Pneumatic Actuator

Type: Double-acting or Spring-return (single-acting)

Model and specifications

Stroke time (actuation speed)

2.Solenoid Valve

Type: Single control or Double control

Operating voltage (e.g., 24V DC, 220V AC)

Explosion-proof requirements

3.Signal Feedback Device

Mechanical or proximity switch

Output type (e.g., current signal, voltage)

Voltage requirements and explosion-proof option

4.Valve Positioner

Type: Electro-pneumatic or Pneumatic

Input signal: 4–20 mA or 0.02–0.1 MPa

Whether an I/P converter is needed

Explosion-proof requirements

5.Air Treatment Unit

Filter pressure regulator

Lubricator for internal valve component protection

6.Manual Operator

Enables emergency manual valve operation when automatic control fails

Pneumatic valve accessories are essential components in any modern automated system. Choosing the right combination of actuators, solenoids, positioners, and air treatment units ensures not only accurate control but also long-term reliability and safety. When configuring pneumatic valve systems, always consider the control requirements, environmental conditions, and safety regulations — especially in hazardous or explosive areas.

Haihao Group provides a full range of pneumatic valve accessories and custom automation solutions. Contact our engineering team for expert guidance tailored to your project requirements. Email:sales@haihaogroup.com